Load cell for crushing rolls



March 21, 1967 o. H. RAMO LOAD CELL FOR CRUSHING ROLLS Original FiledAug. 14, 1962 AT 5 4 Sheets-Sheet 1 INVENTOR.

H. RAMO OLIVER ATTORNEYS March 21, 1967 o. H. RAMO 3,310,244

LOAD CELL FOR CRUSHING ROLLS Original Filed Aug. 14, 1962 4 Sheets-Sheet2 INVENTOR.

OLIVER H. RAMO 082/21, ghWrWgW ATTOR EYS M r h 1967 o. H. RAMO 3,310,244

LOAD CELL FOR CRUSHING ROLLS Original Fil'ed Aug. 14, 1962 4Sheets-Sheet 5 g E r 94 /00 9 i 43;? F I G. 7 9 ix A INVENTOR /0/ i 659a OLIVER H. RAW .99 7/ BY ATTOREEYS March 21, 1967 o. H. RAMO 3,310,244

LOAD CELL FOR CRUSHING ROLLS Original Filed Aug. 14, 1962 4 Sheets-Sheet4 /\L x A INVENTOR OLIVER H. RAMO ATTOR EYS United States Patent3,310,244 LOAD CELL FOR CRUSH-DING ROLLS Oliver H. Raine, NorthAbington, Mass., assignor to Ahington Textile Machinery Works, NorthAbington, Mass a Massachusetts trust Continuation of application Ser.No. 216,856, Aug. 14, 1962. This application Mar. 18, 1965, Ser. No.443,770 11 Claims. (Cl. 241-101) This application is a continuationapplication of my copending application Ser. No. 216,856, filed Aug. 14,1962, and now abandoned.

This invention relates to a novel, self-contained, hydraulic load cellfor weighting and accurately measuring the degree of weighting appliedto crushing or squeezing rolls, more particularly crushing rolls used tocrush and remove trash and undesirable foreign materials from usabletextile fibers.

Crushing rolls are now in common use to crush the undesirable elementsexisting in a carded web of textile fibers. The amount of crushing forceapplied to the nip of the rolls must be great enough to crush theundesirable elements in the carded web but should not be so great as todamage the usable fibers in the web. If too much force is applied to therolls, the usable textile fibers will be exposed to a mutilation whichreduces the length of the fibers.

The use of hydraulic fluid means to apply a crushing force to such rollspermits the utilization of a pressure gauge connected to the hydraulicfluid to determine the degree of crushing force applied to the rolls.However, when a hydraulic cylinder is employed, accurate crushing forcereadings cannot be determined from the pressure gauge reading because ofthe internal friction between the cylinder wall and the leather cupseals or 0 rings of the piston. This break out friction between thesesliding elements results in a false pressure gauge reading used todetermine the crushing force. Furthermore, there is a gradual weeping ofpressurized hydraulic fluid by the piston seals over a period of time(the crushing force is maintained over a long period of time) and meansmust be provided to make up the loss of hydraulic fluid. To overcomethis loss, the cylinder is connected to an outside pressure source orpump, or if the unit is self-contained, a take-up screw may be employed,the body of which displaces an amount of fluid equal to the weepingloss, the fluid pressure being maintained by periodically taking up onthis displacement screw. Eventually, the loss of fluid in theself-contained type of unit must be replaced. Furthermore, leakage ofhydraulic fluid onto the crushing rolls or web causes the web to stickto the rolls.

The use of a flat diaphragm or metal bellows to convert the hydraulicfluid pressure to a crushing force on the rolls eliminates this problemof weeping of fluid. Unfortunately, however, the diaphragm or bellows,when subject to a hydraulic pressure, will stretch and distort andconsequently, its elfective pressure area changes for various positionsof its stroke. For a particular pressure gauge reading, it is notpossible to determine the true crushing force applied on the crushingrolls because of this effective pressure area shift, unless the deviceis calibrated for its various diaphragm stroke positions. Suchcalibration is involved and impractical because the stretch of thediaphragm varies with the applied fluid pressure and causes a variationin stretch. True crushing load readings can only be calculated for avery limited range of stroke in which the effective pressure area shiftof the diaphragm will be at its minimum.

The present invention overcomes the above-mentioned defects by employinga flexible, top hat-shaped rolling Patented Mar. 21, 1967 diaphragm withan annular rolling convolution extending between the side wall of thepiston and the wall of the cylinder. With this type of diaphragm, thedownward movement of the piston causes the vertical wall of theconvolution of the diaphragm to roll off the cylinder Wall, through the180 turn of the convolution and roll on to the vertical side of thepiston. This rolling action is for all practical purposes frictionless.Since there is no sliding contact between the piston and the cylinderwall, there is no break out friction.

Another feature of this type of rolling diaphragm is the fact that theeffective pressure area is constant and does not vary over the entirelength of the piston stroke. The elfective pressure area remainsconstant because there is no change in the Width of the convolution orin the 180 angular turn of the convolution. A downward or upwardmovement of the piston will only change the relative vertical positionof the 180 convolution to the piston or to the cylinder wall. It willnot change the width of the convolution or its 180 angle.

Since the effective pressure area is constant and there is no break outfriction, the force delivered to the crushing rolls is an exact functionof the hydraulic fluid pressure indicated on the pressure gauge,regardless of the position of the piston in its stroke. The forcetransmitted to the rolls is also immediately in response to the internalhydraulic fluid pressure which is indicated by the pressure gauge andwhich is the result of the initial force applied vertically to the topof the piston.

Another feature of the load cell of the present invention is thehermetic sealing of the hydraulic fluid within the unit. There are nosliding mechanical seals as in the case of the cylinder and its slidingpiston, through which there is a weep of oil. No adjustments arenecessary to compensate for the loss of oil, the drop in pressure or thedrop in force transmitted by the unit to the crushing rolls. No outsidepressure source is required to replace the oil loss. Neither is thereany need for an oil displacement screw or its adjustment to compensatefor an oil weep.

The load cell of the present invention combines the good features of thecylinder and piston with the desired features of the diaphragm. Namely,the effective pressure area is constant through the entire length of thestroke as obtained with the cylinder and piston, and the pressurizedhydraulic fluid can be hermetically sealed in a pressure chamber as ispossible when a diaphragm is employed.

It omits the undesirable features of the cylinder and piston, namely,the weep of fluid by the piston packing, and the break out friction ofthe sliding piston seal. It also omits the undesirable features of theflat diaphragm or metal bellows, that is, the changes or shift ineffective pressure area of the diaphragm for the various positions inits stroke and the limited amount of stroke available to reduce theerror introduced by the effective pressure area shift.

Another object of the invention is to provide an improved hydraulic loadcell unit for transmitting crushing force to crushing rolls,particularly crushing rolls used to remove impurities in textile webs,in which the crushing force can be accurately measured.

Other advantages and objects will be apparent from the followingdescription and the accompanying drawings in which:

FIG. 1 is a left side elevation of a combined take-off and crushing rolldevice embodying crushing rolls for crushing impurities in a cardedcotton web and also embodying an embodiment of the hydraulic load cellof the present invention through which crushing force is transmitted tothe crushing rolls and by means by which such force can be accuratelymeasured;

FIG. 2 is a front elevation of a side and the center portion of thedevice of FIG. 1, the other side being substantially the same as theside shown in the figure;

FIG. 3 is a section taken along the line 3-3 of FIG. 2;

FIG. 4 is a section taken along the line 44 of FIG. 2 showing in sectionthe load cell;

FIG. 5 is a longitudinal section taken along the line 5-5 of FIG. 1showing in section the load cell and the manner in which the crushingrolls are rotatably mounted on the frame;

FIG. 6 is a view in perspective of the diaphragm of FIG. 1 with a partremoved to show the cross-sectional shape;

FIG. 7 is an enlarged view like FIG. 4 of the top portion of the loadcell showing in full lines the piston and diaphragm in the topmostposition of the piston and showing in dotted lines an exaggeratedmovement of the piston downwardly to demonstrate the rolling nature ofthe diaphragm.

With reference to the drawings, 2 represents a combined dofier take-offand crushing roll assembly with an embodiment of the load cell 4 of thepresent invention installed therein.

The assembly comprises (1) a lower, smooth surfaced, metal combinedtake-off and crushing roll 6 (4") rotatably journaled in a pair of lowersupport members 8 by means of reduced end shafts 10 and roller bearings12 in the lower support members, (2) a smooth surfaced, metal, smaller(1") take-off roll 14, rotatably mounted by means of reduced end shafts15 in a pair of blocks 16 mounted for vertical sliding movement invertical guides 18 in a pair of upper support members 29 secured on topof the lower support members 8, the roll 14 being urged downwardlytoward and against roll 6 by springs 22 and screws 23 and (3) an upper,smooth surfaced, metal crushing roll 24 (3) also rotatably mounted inthe upper support members 24 by means of vertically slidable blocks 26in which the roll 24 is journaled and which are mounted on the uppersupport members 29 for vertical sliding movement away from and towardthe lower roll 6 whereby the upper crushing roll can be urged againstthe lower crushing roll by means of the crushing force exerting assemblyof which the load cell 4 is a part.

The lower support members are supported on the card frame 27 immediatelyafter and on either side of the cotton card doifer 28 so that theperipheries of rolls 6 and 14 are closely adjacent the doffer periphery.Roll 6 is driven from the dotfer and rolls 14 and 24 are driven fromroll 6. A scraper blade (not shown) is provided for each roll to cleanthe roll.

The rolls 6 and 14 function to remove the web of fibers from the doifer28 of a conventional cotton card and the rolls 6 and 24 crush theimpurities in the removed web. Thus, the lower roll performs a take-offfunction and a crushing function.

The crushing force exerting assembly 25 comprises l) a horizontallydisposed force transmitting rod 32 mounted at its ends in holes in apair of brackets 34, secured to the tops of upper support members 20,the ends of the rod 32 being secured in their brackets 34 by means ofscrews 36, which also prevent rotation of the rod 32, (2) a bendable,bowed tension rod 38 bowed at its middle and mounted at its ends to rod32 by means of a pair of spaced brackets 37 which are mounted on, andpinned to, rod 32 adjacent the brackets 34 and which have oversize holes39 through which the end portions of the tension rod 38 extend, such endportions being threaded to receive tightening nuts 40 which may betightened or loosened to apply and relieve, respectively, astraightening force to the bowed tension rod, which force is transmittedto the crushing roll 24 through (3) load cell 4 mounted on rod 32 and(4) force applying member 42 having a pair of parallelly disposed rolls44 rotatably mounted therein, which are urged into engagement with topcrushing roll 24 to force such roll toward the lower roll 6.

The bottom surface of force applying member 42 has a pair of parallel,spaced channels 4-3 extending thereacross in a direction parallel to theroll 24 and a single, centrally disposed wider channel 45 extendingthereacross in a direction perpendicular to and intersecting the firstpair of channels, the two shafts 46, on which the two rollers 44 arerotatably mounted each by two axially spaced ball bearing assemblies44a, being mounted in the two narrow channels and the two wider rolls 44being accommodated by the wider cross channel, as shown. Circulargrooves on the shafts 46 form the inner races for the ball bearings. Theshafts 46 are held against rotation by screws 48 frictionally engagingthe shafts 46. A protecting guard plate 50 extending below the member 42in front of the nips between rolls 44 and roll 24 is hingedly mounted bymeans of hinge 52 to the plate 51 bolted to the front side of member 42in front of the front end of channel 45, as shown, such plate beingurged by spring 54 to the position shown in the drawings. This plate 50is to guard against accidentally inserting the fingers between the rolls44 and roll 24 and against crushed trash on the roll 24 passing to suchnips.

The load cell 4 comprises two solid metal blocks 56 and 58 of squarehorizontal cross-section bolted together by four bolts 60 at the cornersto form a single block. The mating surfaces of the blocks having matingcylindrical shaped recesses forming a cavity 62 of round horizontalcross-section divided into a lower hydraulic fluid cavity 64 and anupper piston receiving cavity 66 by a round rolling type diaphragm 68,to be described in greater detail hereinafter, the peripheral portion 71of which is wedged in a liquid-tight manner between the peripheralportions of the lower and upper surfaces of the upper and lower blocks56 and 58, respectively, to secure the diaphragm across the cavity 62 ina liquid tight manner, as shown.

The lower block 58 has a horizontal passage 69 extending therethroughparallel to the axis of the roll 24 and receiving the rod 32, as shown.Lower block 58 also has a pair of passages 70 therein leading from thefloor of the hydraulic fluid cavity 64 to the front and rear surfaces 65of the block 58, each passage comprising a vertical portion 72 and awider horizontal portion 74, the ends of which are threaded at 76. Apressure gauge is threaded in one of the passages 74, as shown, thepassage 70 to which the gauge is attached providing communicationbetween the hydraulic fluid chamber 64 and the gauge. The other passage70 is plugged in a liquid tight manner by threaded plug 82. The ends ofa pair of spaced threaded set screws 86, received in a pair of spacedthreaded passages 84 in block 58 lying on each side of horizontalpassage 74 in which the plug 82 is received, extend into slight recessesin the rod 32, as shown in FIG. 4, to secure the load cell to the rod 32and prevent rotation of the load cell 4 around the rod due to therotation of the upper crushing roll 24. Note that the horizontalportions 74 of passages 70 are coaxial, the center-lines of the axesthereof intersecting the center axis of the horizontal passage 69 androd 32 received therein. Thus, the load cell 4 is mounted on the centralportion of rod 32 by means of passage 69.

The lower surface of block 58 has a ball socket 88 which receives theupper part of a force transmitting ball 90, the lower part of the ball90 being received in the ball socket 92 in the upper surface of member42. Crushing force is transmitted from the load cell to the member 42through this ball. However, it and the ball sockets can be eliminatedand the load cell 4 rigidly secured to the top of member 42 with thelower surface of the load cell in abutting relation with the uppersurface of the member 42. In such case, set screws 86 can be omitted andhole 69 can be elongated vertically to allow the load cell to freelymove vertically with respect to rod 32. With the use of a ball 90, thedimensions of the ball and sockets 88 and 92 are such that the lowersurface of the load cell is spaced slightly above the upper surface ofthe member 42 to permit universal movement between the load cell andmember 42.

The lower hydraulic fluid cavity 64 below the diaphragm 68 and thepassages 70 are full of hydraulic fluid, as shown, such cavity and thepassages 70 being hermetically sealed and hence liquid tight except forcommunication with gauge 80. Since the pressure gauge is incommunication with the hydraulic fluid cavity, hydraulic fluid pressurein the cavity 64 is registered by the gauge.

A cylindrical-shaped vertical passage 93 extends from the center portionof the top wall of cylindrical-shaped piston cavity 66 to the centerportion of the top wall of upper block 56.

Horizontally disposed Within the piston cavity 66 is a cylindricalpiston 94, the lower flat surface of which lies flat on the top of themiddle sunken crown portion of diaphragm 68. The diameter of the pistonis less than the diameter of cavity 66 to form an annular space 96 inwhich is received the annular 180 upwardly extending convolution of fold98 of the rolling diaphragm 68, consisting of two parallel verticalwalls 97 and 99 joined by rounded fold 101, the action of which will bedescribed in greater detail hereinafter. The inner vertical wall 97 ofthe convolution lies against and along the side of the piston and theouter vertical wall 99 of the convolution l-ies against and along theside wall of cavity 66. Piston 94 has a central shank 100 extendingupwardly into passage 93 to which is secured a piston rod 102 by meansof threaded bolt 104, threaded in avertical threaded passage 106 inshank 100. Piston rod 102 is slidably received in passage 93. Except forthe enlarged lower portion 103, the portion of the piston rod 102received within passage 93 is sutficiently smaller in diameter than thepassage 93 to provide a slight space therebetween. The fit betweenenlarged portion 103 and the passage 93 is snuglbut slidable. Thisarrangement prevents undue friction from side thrusts due to unequaltake-up of tension rod 38. Piston rod 102 has a central passageextending therethrough comprising an upper portion 108, a reduced middleportion 110, and a lower enlarged portion 112 in which is snuglyreceived the shank 100 of the piston 106, as shown. The middle portionof the passage snugly receives the shank of bolt 104 and the upperportion 108 receives the head of the bolt, such head engaging theshoulder formed by the juncture of 108 and 110. The piston rod 102extends upwardly a substantial distance above the top surface of theblock 56 and the enlarged upper portion 114 thereof has a horizontalgroove 116 extending thereacross above the passage 108 in a directionparallel to the roller 24, such groove receiving the bowed, middleportion of tension rod 38.

The diaphragm 68 prevents any hydraulic fluid from entering the pistoncavity.

Tightening of the nuts 40 on the tension rod 33 tends to straighten thetension rod against the piston rod 114 of the load cell, therebyexerting a downward crushing force on the piston rod. Such force istransmitted to the hydraulic fluid in cavity 64 through piston 94 anddiaphragm 68. Such force is transmitted through the hydraulic fluid tothe lower block 58 and thence, through the ball 90 and member 42 androllers 44, to the upper crushing roll 24 to thereby urge it toward thelower roll 6 to crush impurities in the web passing between rolls 24 and6. The mechanical force applied to the hydraulic fluid by the piston isconverted into hydraulic pressure in the fluid which is accuratelymeasured by the gauge 80. Thus, the crushing force is accuratelymeasured by the gauge so that the exact force desired can be accuratelyset and reset to crush the impurities but not injure the particularfibers being processed. Operators can check the pressure at a glance andcan reset the pressure value while the machine is running or whenchanging grades of fibers.

The rolling diaphragm seal 68 is sold by Bellofram Corporation,Burlington, Mass, and is described on pages 1 to 6 of the Jan. 19, 1961,issue of Machine Design. It is sold under the name Bellofram RollingDiaphragm and is made of a flexible rubberized fabric. Such diaphragmprovides a seal preventing loss of hydraulic fluid by leakage. Diaphragm68 has the general shape of a top hat with the middle portion of thecrown thereof caved or sunken in or recessed where the bottom of thepiston rests on it to thereby provide the annular convolution or pleat98 located between the cylindrical side of the piston and the verticalwall of the cylindrical cavity 66.

FIG. 7 demonstrates the operation of the diaphragm. Note that ondownward movement of the piston from its topmost position shown in fulllines, the convolution 98 of the flexible diaphragm rolls down away fromthe side wall of the cavity 66 (cylinder) and onto (up with respect tothe piston) the side wall of the downwardly moving piston, i.e. it rollsfrom the cylinder wall to the piston wall without sliding friction anddoes not scuff along the wall as is the case with 0 rings and leathercup seals. Because of the fact there is no break-out friction orstretching to overcome, the force applied to the upper roller 24 is veryresponsive to changes in force applied to the load cell. Thus, the forcemay be set at the exact required value not just an approximation of itas in the case of flat diaphragms or conventional bellows. The pistonmovement shown in FIG. 7 is greatly exaggerated to demonstrate therolling operation of the diaphragm. Actually, only very slight movementoccurs, e.g. 0.036" over a range of 0 to 200 lbs. per square inchpressure.

Another advantage of such a diaphragm is that its effective working areais constant to within 0.1% throughout the length of the stroke. Becauseof this feature, the force delivered to the rollers 44 is always anexact function of the indicated pressure, regardless of the pressuremagnitude or the position of the piston. This is not true with flatdiaphragms or bellows.

The diaphragm has extremely long flex life and is compatible with thehydraulic fluid. Although only 0.020" thick it can withstand pressuresup to 1450 lbs. per square inch (bursting point), which is far beyondany pressure used for crushing textile webs. It is noted that thisdiaphragm functions as a pressure diaphragm only at the convolution, therest being backed by the piston.

The above description and accompanying drawings are for the purpose ofillustration only and it is not intended that the invention be limitedthereto or thereby, such invention being defined by the following claimsand including all equivalents thereof.

I claim:

1. A self contained hydraulic pressure transmitting load cell comprisinga block having an internal cavity, a top hat-shaped rolling flexiblediaphragm separating said cavity into a hydraulic fluid containingchamber and a piston chamber, a pressure gauge, a passage. in said blockproviding communication between said hydraulic fluid chamber and saidgauge, said hydraulic fluid chamber being hermetically sealed except forsaid communication with said gauge and containing hydraulic fluid, apiston within said piston chamber and supported on said diaphragm, avertical bore extending from the top of said block to said pistonchamber, said bore receiving a piston rod attached to said piston forapplying a load to said block through said diaphragm and hydraulicfluid, bearing means at the bottom of said block for transmitting saidload to a working member, said gauge indicating the magnitude of saidload applied to said working member, said diaphragm having an annularrolling convolution, which is rolled by movement of said piston.

2. A load cell according to claim 1, said block being mounted on a rodextending through a transverse passage through said block.

3. A load cell according to claim 1, said bearing means comprisingbearing means for transmitting said load to a rotating roll,

4. A load cell according to claim 1, the side of said piston bing spacedfrom the side wall of the piston chamber to form an annular spacetherebetween, said diaphragm having an annular 180 convolution extendinginto said space between and along the side of the piston and the wall ofthe piston chamber.

5. A load cell according to claim 4, the shape of said diaphragm beingthat of a top hat with the center portion of the crown being recessed toform said annular convolution, said convolution being defined by thevertical wall of the recess and the parallel side wall of the crown, thejuncture thereof forming a 180 fold.

6. A load cell according to claim 1, said bearing means comprising apair of rotatable rolls.

7. A load cell according to claim 5, said block being formed by a pairof blocks, the opposed faces of which are provided with opposingrecesses forming said cavity, the peripheral portion of said diaphragmbeing clamped between said blocks so as to be positioned across saidcavity to divide it into said hermetically sealed hydraulic fluidchamber and said piston chamber.

8. In combination, a pair of textile fiber web crushing rolls, means forexerting a crushing force on one of said rolls to force it toward theother to provide a crushing function, said force exerting meanscomprising a self contained hydraulic pressure transmitting load cellcomprising a block having an internal cavity, a top hatshaped rollingflexible diaphragm separating said cavity into a hydraulic fluidcontaining chamber and a piston chamber, a pressure gauge, a passage insaid block providing communication between said hydraulic fluid chamberand said gauge, said hydraulic fluid chamber being hermetically sealedexcept for said communication with said gauge and containing hydraulicfluid, a piston slidable within said piston chamber and supported onsaid diaphragm, a vertical bore extending from the top of said block tosaid piston chamber, said bore slidably receiving a piston rod attachedto said piston, means for asserting a mechanical force on one of saidblock and said piston, whereby said force is transmitted through saidhydraulic fluid to the other of said block and piston,

and means for transmitting said force from said other of said piston andblock to said one roll.

9. A combination according to claim 8, the side of said piston beingspaced from the side Wall of the piston chamber to form an annular spacetherebetween, said diaphragm having an annular 180 convolution extendingupwardly therefrom into said annular space between the piston and thewall of the piston chamber.

10. A combination according to claim 9, the shape of said diaphragmbeing that of a top hat with the center portion of the crown beingrecessed to form said annular convolution, said convolution beingdefined by the vertical wall of the recess and the parallel side wall ofthe crown, the juncture thereof forming a 180 fold.

11. A self contained hydraulic pressure transmitting load cellcomprising a block having an internal cavity, a top hat-shaped rollingflexible diaphragm separating said cavity into a hydraulic fluidcontaining chamber and a piston chamber, a pressure gauge, a passage insaid block providing communication between said hydraulic fluid chamberand said gauge, said hydraulic fluid chamber being hermetically sealedexcept for said communication with said gauge and containing hydraulicfluid, a piston within said piston chamber and supported on saiddiaphragm, a vertical bore extending from the top of said block to saidpiston chamber, said bore receiving a piston rod attached to said pistonfor applying a load to said block through said diaphragm and hydraulicfluid, bearing means at the bottom of said block for transmitting saidload to a working member, said gauge indicating the magnitude of saidload applied to said working member.

References Cited by the Examiner UNITED STATES PATENTS 2,075,156 3/1937Albero 241-167 2,563,690 7/1951 Nalon 308-9 2,669,866 2/1954 Holmes.2,911,606 11/1959 Hoffman 73-406 X ROBERT C. RIORDON, Primary Examiner.

D. G. KELLY, Assistant Examiner.

11. A SELF CONTAINED HYDRAULIC PRESSURE TRANSMITTING LOAD CELLCOMPRISING A BLOCK HAVING AN INTERNAL CAVITY, A TOP HAT-SHAPED ROLLINGFLEXIBLE DIAPHRAGM SEPARATING SAID CAVITY INTO A HYDRAULIC FLUIDCONTAINING CHAMBER AND A PISTON CHAMBER, A PRESSURE GAUGE, A PASSAGE INSAID BLOCK PROVIDING COMMUNICATION BETWEEN SAID HYDRAULIC FLUID CHAMBERAND SAID GAUGE, SAID HYDRAULIC FLUID CHAMBER BEING HERMETICALLY SEALEDEXCEPT FOR SAID COMMUNICATION WITH SAID GAUGE AND CONTAINING HYDRAULICFLUID, A PISTON WITHIN SAID PISTON CHAMBER AND SUPPORTED ON SAIDDIAPHRAGM, A VERTICAL BORE EXTENDING FROM THE TOP OF SAID BLOCK TO SAIDPISTON CHAMBER, SAID BORE RECEIVING A PISTON ROD ATTACHED TO SAID PISTONFOR APPLYING A LOAD TO SAID BLOCK THROUGH SAID DIAPHRAGM AND HYDRAULICFLUID, BEARING MEANS AT THE BOTTOM OF SAID BLOCK FOR TRANSMITTING SAIDLOAD TO A WORKING MEMBER, SAID GAUGE INDICATING THE MAGNITUDE OF SAIDLOAD APPLIED TO SAID WORKING MEMBER.